RICHMOND -- A supervisor with the food stamps unit of the Contra Costa Employment and Human Services Department was arrested Thursday on charges of embezzling thousands of dollars in public funds, falsifying records and identity theft.

Tina Crosby, 46, was arrested after a joint investigation by the Contra Costa County District Attorney's Office and the department's fraud unit. An investigation showed that the woman, while working at a computer at the department's Richmond office, reopened a previously closed file and made false entries resulting in unauthorized benefits of $1,082 in cash aid and $1,826 in unauthorized Electronic Benefit Transfer card benefits, authorities said.

The District Attorney's office also stated that the investigation revealed that Crosby had made numerous additional deposits of public funds to the fraudulent card account.

Crosby also is accused of making cash withdrawals and grocery purchases with the card, according to the District Attorney's office.

The total amount of public assistance embezzled was nearly $5,400, officials said.

Crosby has been charged with four felonies and faces a maximum of four years in state prison if convicted.

Suspected public assistance fraud can be reported to the District Attorney's Office at 925-957-8604.